1. Field of the Invention
The present invention relates generally to the field of surgical devices. In particular, this invention relates to anchors for attaching soft tissue to bone, and or to other soft tissue.
2. Background of the Invention
There are a number of conventional devices currently being marketed as anchors for securing soft tissue to bone. These devices have found application in surgical repair procedures throughout the human body. The conventional devices have some disadvantages which render them less than optimal for use in many operative procedures.
Conventional devices are generally metal, plastic or absorbable anchors which are screwed or press fit into predrilled holes in a bone. The conventional anchors have a suture-securing hole transverse to the long axis of the anchor. The suture-securing hole is generally located in the shank of the anchor which is therefore at or near the surface of the bone when the anchor is properly seated in the bone. The orientation of the suture securing hole in conventional anchors typically requires that the anchor have the suture threaded through the suture-securing hole, before the anchor is secured to the bone. A surgeon has little or no choice of the angle or position of tissue approximation, that is of attachment, when using such conventional anchors. Once a conventional anchor is secured in place, a surgeon is generally not able to rethread a suture through the suture-securing hole if the suture should break or otherwise come loose. Usually, a new anchor kit needs to be opened if the suture breaks. This leads to the inefficient use of the patient""s operative time as well as the surgeon""s time. Conventional anchors also only accommodate one suture per anchor and surgeons have little or no choice of suture material to be used with a particular anchor since the anchor kits are preloaded or come with a specific suture type.
Such conventional anchors require a surgeon to follow many steps and use special tools to successfully load and use the conventional anchors. First, the surgeon must gather the special tools necessary to use the conventional anchor. Second, the surgeon must thread the suture provided with the conventional anchor using a specialized threading tool. Third, the surgeon must drill an anchor hole into the bone which will secure the conventional anchor. Fourth, the surgeon must attach a conventional anchor to a special insertion tool. Fifth, the surgeon must secure the conventional anchor into the hole prepared in step three. Sixth, the surgeon must apply an appropriate surgical needle to an end of the free suture. Seventh, the surgeon must approximate the soft tissue to the conventional anchor using the needle and suture.
In accordance with the present invention, a soft tissue securing anchor is provided with one or more anchor holes distributed around the perimeter of the head of the anchor in a variety of orientations.
A soft tissue securing anchor according to the present invention may be used to secure soft tissue to bone, or to reapproximate a plurality of soft tissue points to a single bone site or to approximate soft tissue to soft tissue. The materials from which a soft tissue securing anchor are fabricated may be the same as conventional anchors, i.e. an inert material. Specific materials that may be used include plastic, stainless steel, titanium alloys, or absorbable materials. Thus a soft tissue securing anchor according to the present invention has the same effect on a body in which it is surgically secured as conventional anchors. Additionally, all types of conventional absorbable or non-absorbable sutures may be used with the present invention.
In a first aspect of the present invention, the anchor holes are inclined so that with the soft tissue securing anchor seated in the bone, the upper and lower apertures of each anchor hole are accessible to attach separate sutures to each of the anchor holes using conventional surgical techniques, i.e. curved needles. Any other variety of surgical needles may also be used. Additionally, free sutures, without attached needles may be threaded through these holes. The inclined anchor holes allow a surgeon to efficiently attach soft tissue to the soft tissue securing anchor using her preferred surgical tools without the necessity of using a multiplicity of specialized tools. Thereby making any given surgery more efficient and cutting down on costly operative time as well as time that the patient is exposed to potentially life-threatening anesthesia. The presence of a plurality of anchor holes in a single soft tissue securing anchor permits a surgeon to secure a plurality of soft tissue points with fewer soft tissue securing anchors than she would have been required using conventional anchors that only accommodate a single suture.
In another aspect of the present invention, the lower surface of the anchor head is angled relative to the long axis of the soft tissue securing anchor. The angle chosen is dictated by the surgeon""s choice of needle and suture for a particular application. The angle of the lower surface of the anchor head combined with the angle of the anchor holes allows the surgeon to efficiently attach one or more sutures to a single soft tissue securing anchor. This minimizes the amount of foreign bodies that are surgically placed in a patient""s body. Foreign body tissue reaction may lead to an increased rate of infection and, therefore, with the present invention, the patient would benefit with a lowered rate of foreign body tissue reaction. Additionally, since the suture to anchor body interface is very important with respect to operative stability, the possibility of now securing multiple soft tissue points to one anchor via the present invention means that if a single suture were to break, the operative approximation of soft tissue to bone or soft tissue to soft tissue would not be lost, as it is with the breaking of a suture attached to a conventional anchor.
In a further aspect of the present invention, each aperture of each anchor hole is chamfered to accommodate surgical needles. The chamfered aperture simplifies the surgeon""s task of introducing the surgical needle into the anchor hole by widening the entry and exit apertures, and thus funneling the surgical needle point to the center of the anchor hole. The chamfer also lessens the angle of approximation the surgeon must achieve with, a surgical needle to successfully pass the surgical needle and suture through the anchor hole. The chamfered areas, from the anchor hole to the outside edge, shall be polished or somehow smoothed to remove sharp edges and rough areas which may cause friction and abrasion of the tissue-approximating suture or the soft tissue itself. The chamfered aperture also minimizes acute edges in contact with the suture to minimize abrading of the suture thus allowing the liberal use of sliding knots on sutures passing through the present invention.
In a still further aspect of the present invention, an anchor for securing soft tissue to bone or soft tissue to soft tissue includes a conventional attachment means having a long axis and a head at a first end of the long axis, a means to accommodate a securing or drive tool, and an anchor hole through the head, the anchor hole has an upper aperture and a lower aperture. The anchor hole is oriented to cause a line through the center of the anchor hole to intersect an extension of the long axis beyond the head.
In a still further aspect of the present invention, an anchor for securing soft tissue to bone or soft tissue to soft tissue includes an attachment means having a long axis and a head at a first end of the long axis, a means to accommodate a securing or drive tool, and an anchor hole through the head, the anchor hole having an upper aperture and a lower aperture, the anchor hole oriented to cause a line through the center of the anchor hole to be skew to the long axis.
In another still further aspect of the present invention, a surgical anchor for reapproximating soft tissue to bone or soft tissue to soft tissue includes a screw having a head, a shank and a threaded end, a shoulder between the body and the shank to provide a visual and tactile reference for proper head height above the bone, a means to accommodate a securing or drive tool, and a plurality of generally radial anchor holes disposed about the circumference of the head and extending through the head, each anchor hole describing an angle between 0 and 75 degrees from the shank to a line through the anchor hole.
These and other features and advantages of this invention will become further apparent from the detailed description and accompanying figures that follow. In the figures and description, numerals indicate the various features of the invention, like numerals referring to like features throughout both the drawings and the description.